This invention relates generally to lightweight porous fiber reinforced thermoplastic polymer sheets, and more particularly to lightweight porous fiber reinforced thermoplastic polymer sheets that include reinforcing skins.
Lightweight porous fiber reinforced thermoplastic sheets have been described in U.S. Pat. Nos. 4,978,489 and 4,670,331 and are used in numerous and varied applications in the product manufacturing industry because of the ease of molding the fiber reinforced thermoplastic sheets into articles. Known techniques, for example, thermo-stamping, compression molding, vacuum forming, and thermoforming have been used to successfully form articles from fiber reinforced thermoplastic sheets.
Tougher automotive fuel economy standards are requiring an overall vehicle weight reduction to meet these standards. Traditional vehicle seat back systems are made from stamped steel or blow molded plastics. Steel stamping dies are a huge capital investment. Although a steel seat back is thin, the steel material is very dense compared with polymers. Steel seat back can range from about 3 lbs to 6 lbs. The steel seat back is spot welded to the seat frame and structural reinforcements are attached to the corners of the steel seat back to prevent and bending of the steel when a load is applied. Blow molded seat backs are lighter than steel seat backs, but are bulky and can be 50 mm or greater in thickness. Blow molded plastic seat backs are attached mechanically to the seat frame.